1. Field
The present disclosure relates to an oil strainer for a vehicle transmission.
2. Description of the Related Art
Oil used as operating oil and lubrication oil for a transmission mounted in a vehicle is stored in an oil reservoir provided in the bottom portion of a transmission casing. The oil stored in the oil reservoir is pumped up by an oil pump. The oil pumped up from the oil reservoir by the oil pump is supplied to components of a transmission mechanism that require lubrication and a valve body of an oil pressure control unit. Thereafter, the oil flows back to the oil reservoir.
The transmission casing has an oil strainer mounted therein. The oil strainer filters the oil drawn by the oil pump (refer to, for example, Japanese Unexamined Patent Application Publication No. 2005-291408). The oil strainer includes a hollow body case (a main body) having a filtering member (a filter) therein and a suction port through which oil is drawn into the body case. By operating the oil pump disposed downstream of the oil strainer, the oil drawn through the suction port is filtered and is delivered to the oil pump.
At that time, the suction port of the oil strainer is an opening formed in, for example, the bottom surface of the body case and remains submerged in oil stored in the transmission casing. However, if the oil is pressed to one side of the transmission casing due to rapid acceleration/deceleration or acceleration in turn during travelling of the vehicle, the suction port may be exposed to the air at the oil surface. Thus, there is a risk of air getting involved in the oil drawn through the suction port (i.e., the occurrence of ventilation).
Therefore, according to an oil strainer of existing transmissions, the amount (the absolute amount) of oil in a transmission casing is increased to prevent the suction port of the oil strainer from being exposed to the air even when the oil is pressed to one side of the transmission casing due to rapid acceleration/deceleration or acceleration in turn during travelling of the vehicle.